CN1191688C - Method and device for amplifying and controlling signals transmitted by mobile terminal - Google Patents

Abstract

The procedure for the monitoring of an amplification signal emitted from a radio-communication terminal comprising a power amplifier (1) and voltage supply battery (10) entails the detection of the output power (Pout) of the amplifier and converting this power into a detected voltage (Vdet) and comparing this with a reference voltage (Vref). At least one of the detected or reference voltages is produced depending upon the voltage of the supply battery and this before the stage of comparing the detected voltage with the reference voltage.

Description

Method and device for amplifying and controlling signals transmitted by mobile terminals

technical field

The invention relates to a wireless terminal, such as a portable wireless phone, and in particular to a method and device for controlling the amplification and control of a signal transmitted by a mobile terminal capable of reducing the energy consumption of the terminal's power supply battery.

Background technique

Mobile terminals of the portable telephone type have a power amplifier capable of transmitting a signal with sufficient power for communication.

We know that every telephone must constantly be connected to a terminal in order to make and receive calls. The farther the phone is from the terminal, the greater the transmit power must be.

According to the GSM network specification (Global System for Mobile communications Global System for Mobile Communications), the maximum power that a terminal must be able to transmit when operating on the network must be 33dBm. This maximum power can be reduced to 30.5dBm in extreme cases, that is to say when the battery voltage drops.

Therefore, if the phone is too far from the terminal it is connected to, it requires the phone's maximum power to operate correctly.

However, the greater the transmission power, the greater the amplification of the terminal, so the terminal also requires a larger battery. This results in a large drain on the battery and thus the duration of the phone is significantly reduced.

Contents of the invention

In this context, the object of the invention is to overcome this drawback by using a method and a device capable of amplifying the signal of a mobile terminal and reducing the energy consumption of the battery of said terminal.

For this reason, according to the invention, the amplification control method of radio communication terminal transmission signal comprises a power amplifier (1) and a voltage (Vbat) power supply battery (10), and described method comprises the following steps:

- detecting (3) the output power (Pout) of the amplifier (1) and converting this power (Pout) into a detection voltage (Vdet),

- comparing said detected voltage (Vdet) with a set voltage (Vref);

- changing the input voltage (Vc) of the power amplifier (1) according to the result of the comparison,

It is characterized in that at least one of the detection voltage (Vdet) or the setting voltage (Vref) is supplied depending on the voltage (Vbat) of the power supply battery (10), and it is between the detection voltage (Vdet) and the setting voltage (Vref) Before the comparison step.

According to a first implementation form, the detection voltage is increased from a correction value dependent on the supply battery voltage.

According to a second implementation form, the set voltage is reduced from a correction value dependent on the supply battery voltage.

Preferably, the correction value is a multiple of (Vbat-Vnom), where (Vbat) is the voltage of the power supply battery, and (Vnom) is its nominal voltage.

Preferably, at least one of the detection voltage (Vdet) or the set voltage (Vref) is only dependent on the voltage (Vbat ).

The invention also relates to a device for amplifying and controlling terminal transmission signals, including a power amplifier, a device for detecting the output power of the amplifier and converting the power into a detection voltage, a device for comparing the detection voltage with a set voltage, and a device for controlling the input voltage of the amplifier and a voltage supply battery, characterized in that it comprises means for supplying a detection voltage (Vdef) or a set voltage (Vref) dependent on the voltage (Vbat) of the supply battery (10), and which is at the detection voltage (Vdet) Before the comparison step with the set voltage (Vref).

According to a first realization, the means for taking into account the supply battery voltage comprise a subtractor arranged between the detection and amplifier power conversion means and the comparison means.

Preferably, the device also includes a detection voltage (Vdet) or a set voltage (Vref) that can only provide a detection voltage (Vdet) or a set voltage (Vref) depending on the voltage (Vbat) of the power supply battery (10) only when the range of the amplifier output power (Pout) is close to 30 dBm One of the locking devices, said locking device preferably includes a field effect transistor.

According to a second realization, the means for providing either a detected voltage (Vdet) or a set voltage (Vref) dependent on the voltage (Vbat) of the supply battery (10) comprises only ) software device when the range is close to 30dBm.

In addition, a wireless communication terminal including the amplification control device according to the invention is also provided.

Description of drawings

The invention will be better understood from an illustrated limited embodiment with reference to the accompanying drawings, in which:

- Fig. 1 is a schematic diagram of a mechanism that makes the amplification control method of the mobile terminal transmit signal put into application according to the background technology;

- Figure 2 is a schematic diagram of a first realization of a device capable of putting into practice the method according to the invention;

- Figure 3 is a schematic diagram of a second realization of a device capable of putting into practice the method according to the invention.

Detailed ways

FIG. 1 schematically shows a device capable of applying an amplification control method for a signal transmitted by a mobile terminal, such as a portable phone, according to the background art.

Signal amplification is performed by a power amplifier (1) powered by constant input power (Pin), which comes from a pre-amplifier (not shown), and output power (Pout) is transmitted through the mobile terminal antenna 2.

The mechanism also includes an output power detection and conversion device 3 of the power amplifier 1 . The detecting means 3 detects the output power (Pout) of the power amplifier 1 and then converts it into a voltage (Vdet) corresponding to the detected voltage at the output of the detecting and converting means 3 .

Said detection output voltage (Vdet) is then sent to comparator 4 in a known manner.

The comparator 4 comprises two variable resistors 5a, 5b, each of which may be a variable capacitor 6, and an operational amplifier 7, one of its inputs 7a being connected to ground.

The two inputs of the comparator 4 are thus formed by the detection voltage (Vdet), which maps the output power (Pout) of the power amplifier 1, and the set or reference voltage (Vref) from a digital-to-analog converter 8 in a known manner.

According to the result of the comparison between (Vdet) and (Vref) performed by the comparator 4 , the comparator will output an output voltage (Vs), which is sent to the control means 9 .

Said control means 9 consist of a control circuit for regulating the control voltage (Vc) at the input of the power amplifier according to the output voltage (Vs) from the comparator 4 .

To ensure its operation, the power amplifier 1 is also powered by a supply battery 10 which provides a voltage (Vbat).

Thus, depending on the signal amplification to be achieved, the amplifier 1 calls more or less for the power supply battery 10 . Especially when the mobile terminal is far away from the fixed terminal to which it is connected, the transmitting power (Pout) must be the maximum, that is to say 33dBm according to the recommendation of the GSM standard.

This maximum power required by the fixed terminals results in a large drain of energy from the supply battery 10, which results in a substantial reduction in the duration of the mobile terminal.

Fig. 2 briefly shows a first implementation form of a mobile terminal transmission signal amplification control device capable of putting the method according to the invention into use.

Components in FIG. 2 that are the same as those in FIG. 1 have the same reference numerals.

We can thus find the power amplifier 1 , the detection and conversion means 3 , the comparator 4 control circuit 9 , and the power supply battery 10 .

The fundamental difference to the background art device is at the detection/conversion stage of the output power (Pout) of the power amplifier 1 .

In fact, the device according to the invention comprises means 11 for taking into account the supply battery 10 voltage (Vbat) when detecting/converting the output power of the power amplifier.

Said means 11 comprise a subtraction module 12 and locking means constituted, for example, by a field effect transistor 13 . Due to the effect of the locking device, below a certain power Pout threshold, the field effect transistor will not conduct and lock the effect of the subtractor.

Both the subtraction module 12 and the field effect transistor 13 are connected to the circuit between the output voltage detection means 3 of the power amplifier 1 and the input of the comparator 4 .

The subtraction module 12 is configured to output the following output voltage (V'det):

(V'det)=(Vdet)-K(Vbat-Vnom)

here:

(Vdet) is the detection voltage directly at the output of the detection device 3

K is a positive multiplication coefficient;

(Vnom) is the nominal voltage of the power supply battery 10 .

Therefore, the smaller the supply battery voltage (Vbat), the larger the difference between (Vbat)−(Vnom).

Considering the voltage (Vbat) of the power supply battery can reduce the difference between the detection voltage at the output of the detection and conversion means 13 and the set voltage (Vref).

Therefore, the closer the voltages (V'det) and (Vref) are, the less the power amplification between (Pin) and (Pout) is, and the less the supply battery 10 is needed.

The smaller the need for the battery 10, the longer its duration will be.

According to the GSM standard recommendation, a maximum power transmission of less than this requirement (33dBm) is possible in some cases, especially when the battery voltage (Vbat) weakens.

Field effect transistor 13 provides operation of the device only for certain output power (Pout) ranges.

In fact, the field effect transistor 13 is only conductive for values of high output power (Pout), for example starting from 30 dBm (thus considering the battery voltage (Vbat)).

Due to this configuration, the output power (Pout) of the amplifier 1 is only dependent on the voltage (Vbat) of the battery 10 when the transistor 13 is turned on, that is to say when the required output power (Pout) reaches a certain level.

Thus, for low output powers (Pout), the transistor 13 is non-conductive: thus the voltage (Vbat) of the supply battery 10 is not taken into account and the device works according to the methods of the prior art.

Fig. 3 briefly shows a second implementation form of the mobile terminal transmission signal amplification control device capable of putting the method according to the invention into use.

Again, those parts that are the same as in Figures 1 and 2 have the same reference numerals.

In the case of FIG. 3, the supply battery voltage (Vbat) is considered when establishing the set voltage (Vref).

Said supply battery voltage (Vbat) is passed through a digital/analog converter 14, while software means 15, known per se, will, by means of an algorithm, calculate the output power (Pout) at the amplifier 1 and the supply battery voltage ( Vbat), to establish a set voltage (Vref).

The detection voltage (Vdet) remains constant in this implementation.

For simplicity, the algorithm of the software means 15 may for example be of the following type:

If (Pout) > (Plim),

Then (Vref)'=(Vref)+K'(Vbat-Vnom)

here:

(Plim) is the limit value of the amplifier 1 output power (Pout), chosen by the designer,

(Vref) is the set voltage when the battery voltage (Vbat) is not considered (thus when (Pout)<(Plim)),

K' is a positive multiplication coefficient;

(Vnom) is the nominal voltage of the power supply battery 10 .

At the output of the software means 15 there is another digital/analog converter 16 in order to obtain voltages (Vref) or (Vref)', said software means 15 not actually working on these voltages but being able to control them.

Therefore, starting from a limit value (Plim) of the output power (Pout) of the amplifier 1, the set voltage (Vref) takes a value (Vref)' dependent on the battery voltage (Vbat).

The coefficient K' is chosen to be positive, the correction voltage (Vref)' is smaller than (Vref), as in the first implementation, which reduces the difference between the detection voltage (Vdet) and the set voltage (Vref)' .

The difference is reduced, the amplification between input power (Pin) and output power (Pout) is smaller.

The need for the power supply battery is thus reduced, increasing its duration.

Thus, for high powers (for example starting from 30 dBm), the device takes into account the voltage (Vbat) of the supply battery 10 in order to limit the power amplification so that the supply battery 10 energy is more economical.

Another advantage of the device and method according to the invention is the ability to avoid saturation of the power amplifier 1 when the mobile terminal is, for example, close to a fixed terminal to which it is connected.

Claims (12)

1. the amplification control method that transmits of radio-communication terminal comprises a power amplifier (1) and a voltage (Vbat) supplying cell (10), and described method comprises the following steps:

-detect the power output (Pout) of (3) amplifier (1) and convert this power (Pout) to detection voltage (Vdet),

-described detection voltage (Vdet) is compared with setting voltage (Vref),

-change the power output (Pout) of power amplifier (1) according to comparative result,

It is characterized in that detecting in the two one of voltage (Vdet) or setting voltage (Vref) and depend on the voltage (Vbat) of supplying cell (10) and be provided, and it is before detecting voltage (Vdet) and setting voltage (Vref) comparison step.

2. method according to claim 1 is characterized in that detecting voltage (Vdet) and is increased the corrected value that depends on supplying cell (10) voltage (Vbat).

3. method according to claim 1 is characterized in that setting voltage (Vref) is reduced the corrected value that depends on supplying cell (10) voltage (Vbat).

4. according to the described method in one of claim 2 or 3, it is characterized in that corrected value is the doubly value that the voltage (Vbat) of described supplying cell (10) deducts the nominal voltage gained difference of supplying cell (10).

5. method according to claim 1 depends on the voltage (Vbat) of supplying cell (10) when it is characterized in that detecting at least one in the two of voltage (Vdet) or setting voltage (Vref) and only be in the limited field of the power output (Pout) of amplifier (1).

6. method according to claim 5 is characterized in that detecting at least one in the two of voltage (Vdet) or setting voltage (Vref) and only is the voltage (Vbat) that depends on supplying cell (10) in the power output (Pout) of amplifier (1) during near the scope of 30dBm.

7. amplification control appliance that terminal transmits, comprise a power amplifier (1), the device (3) that detects described amplifier (1) power output (Pout) and this power (Pout) is converted to detection voltage (Vdet), detect the comparison means (4) of voltage (Vdet) and setting voltage (Vref), amplifier (1) input voltage (Vc) control device (9) and a voltage (Vbat) supplying cell (10)

It is characterized in that it comprises is used to depend on supplying cell (10) voltage (Vbat) and the device (11) that detects voltage (Vdef) or setting voltage (Vref) is provided, and wherein this providing is before the comparison that detects voltage (Vdet) and setting voltage (Vref).

8. equipment according to claim 7, it is characterized in that for detection voltage (Vdet) that the voltage (Vbat) that depends on supplying cell (10) is provided or setting voltage (Vref) the two one of device (11) comprise one be placed in that power (Pout) detects and conversion equipment (3) and comparison means (4) between subtracter (12).

9. equipment according to claim 7, it is characterized in that it also comprises locking device (13), can only be amplifier (1) power output (Pout) provide during near the scope of 30dBm the detection voltage (Vdet) of the voltage (Vbat) that depends on supplying cell (10) or setting voltage (Vref) the two one of.

10. equipment according to claim 9 is characterized in that being used to provide the locking device of the detection voltage (Vdet) of the voltage (Vbat) that depends on supplying cell (10) to comprise a field-effect transistor (13).

11. equipment according to claim 7 is characterized in that being used to provide the device (11) of the setting voltage (Vref) of the voltage (Vbat) that depends on supplying cell (10) to comprise software service (15).

12. equipment according to claim 11 is characterized in that software service (15) can only be to provide one of the detection voltage (Vdet) of the voltage (Vbat) that depends on supplying cell (10) or the two of setting voltage (Vref) during near the 30dBm scope in amplifier power output (Pout).